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Discussion Starter · #1 ·
  • So I decided to take some pictures of my Defi gauge install after my Shitsport decided to fail after 200km (2nd gauge/sensor to fail). This time I would go with a proven line of gauges and immediately purchased a Defi Red Racer boost gauge promptly after curb stomping my Shitsport into 1000 pieces.

    What I used for this install:

    • Many little zip ties (with rounded edges to prevent vibration cuts/abbrasions)
      Left over computer cable braid (similar to this: braid)
      1/4” ring terminal
      Solder and soldering iron
      3 x Littelfuse Add-a-Circuits
      3 x 1A mini fuses
      Coat hanger
      20AWG wire
      4ft scrap piece of 16-18AWG wire
      White paint pen
      Fire extinguisher (can never be too careful)
      Misc things: wire cutters, needle nose pliars, duct tape, beer, primetimes, girlfriend, etc etc.

    Use these instructions at your own risk! I put this how-to together to give insight into my Defi gauge install and this may or may not suit your tastes. I can’t be held liable for any errors resulting in injury or personal damage due to this write-up. Use this at your OWN risk! With that said, lets begin.

    Installation Tips

    • Label all of your screws and little parts so everything goes back together properly.
      Give yourself a nice time window to do this. Taking your time = quality install.
      Label the wires. More than once about 6 inches apart will help a lot in the event your markings or labeling wears/tears off. I used black wire and coded my wires using a white paint pen utilizing dots to distinguish each at the terminating end.

    I started by inspecting all of the Defi parts and soldered about 4 ft of 20AWG wire to the RED, ORANGE and WHITE wires (+12V Constant, +12V IGN, +12V Illumination) and 2 ft of 20AWG to the BLACK wire (Ground). I then pushed all wires except the ground through the wire braid. I also decided where to mount my gauge - to the left of my instrument cluster hood as I can easily view this area without too much aversion.

    Next disconnect the negative battery terminal and remove the TMIC shroud. It has 2 x 10mm bolts at the front that you will need to remove.

    Remove the drivers side scuff plate.

    Remove the driver side kick panel.

    Detach the left-side of the console trim. I didn’t feel the need to remove the whole thing, but opened up the glove box and started in the middle working my way left.

    Releasing the hood latch is tricky. You need to get on your back and take a look underneath. You will need to angle a small flathead screw driver so that the handle is leaning towards the front of the car. You’ll then have to slide the head of the screwdriver in and gently pry, moving the handle towards the rear of the car while pulling the latch towards the back of the car also. If you pry too hard you will break the clip so take it easy! When you get it once, it’ll take you seconds the next time. Once you’ve got that detached, remove the screw and label it or place it somewhere distinguishable.

    Now you can remove the lower dash. I start by unclipping the OBD-II port (flat head screw driver to release the latch at the top)…

    ..and then pulling the dash from the bottom to release the pressure clips.

    Then remove the instrument cluster hood.

    Unclip the HID leveler, DSC and interior illumination connectors. No need to worry about which goes where because each one is unique. Place the lower dash panel in a safe spot.

    Now this is where I ran my Defi boost sensor harness -- through the hood latch release cable grommet located on the driver’s side up underneath the dash.

    And from the engine bay..

    Since I’ve done this twice I’ve discovered a strategy that I believe works well:

    • Start by straightening a coat hanger and feeding it through the grommet starting from the inside. This is easiest when laying on your back with a really fine flathead screwdriver handy to open the small-mouth of the grommet to get the coat hanger in.

      Once you’ve got it fed through into the engine bay, grab a scrap piece of 16-18AWG wire and pin it with the coat hanger by looping the hanger end over and pinching the wire really, really tight.

      Duct tape the end so it’s tapered and smooth (if you don’t make the entry point smooth chances are it will bunch and cause problems).

      Pull that bitch through. I found it best to get your hand under the dash to hold the grommet so that it doesn’t slide back and get bunched up on the end you are pulling through. With some strong pulls and finesse you will get it through no problem.

  • Now you are half-way there. What you want to do is cut the wire as close to the coat hanger as possible, cut off the end of the coat hanger and pin the other end of the 16-18AWG wire on the engine-side. Once pinned, take the Defi boost sensor wire and duct tape it inline with the coat hanger and pinned 16-18AWG wire. You want to position everything so this apparatus is as thin as possible to minimize the resistance and minimize the chances of messing up the Defi gauge connector.

    Get someone to feed the coat hanger into the grommet from the engine bay while you pull the 16-18AWG wire sitting in the drivers footwell. Placing your fingers on the grommet so that it doesn’t bunch up is a must as there is much more coming through this time. Just take your time and it will come.

    Once you’ve got that sucker in, pull the slack in the sensor harness into the interior. I had my helper hold the harness boost sensor connector right about where I planned on installing the boost sensor and adjusted accordingly.

  • That is pretty much the worst part of the whole process so it gets easier from here. Now I ran the Defi power harness up behind the instrument cluster hood and rested it over the instrument cluster. I did the same with the boost sensor harness.

    Now go under the hood and remove the vacuum hose connecting the BPV to the intake manifold using some needle nose pliars to release the clamps. I measured twice, and cut once – right near the top of the line to place my boost tee. Snug everything up and zip tie all ends.

    Now I found a nice spot for the boost sensor, ran the vacuum hose under the intake and zip tied it down..

    ..then ran the sensor wires behind the battery box and towards the driver-side ¼ panel. I connected the sensor harness (big white connector), covered all wire with wire loom and tucked it away neatly.

    Using wire loom here is a must. I loomed all exposed wire from the sensor to the hood latch grommet.

    Grab your straightened coat hanger and head back to the interior. Remove the right drivers kick panel by removing the panel clip. I ran the RED, ORANGE and WHITE Defi wires over the dash bracing. I made it an easily accessible spot in the event a fuse blows.

    Then I went up and over a metal support in the center column by hand...

    ..and then under the white HVAC channel to the passenger side by taping the wire ends to the straightened coat hanger using duct tape.

    Nice and neat now....

    Remove the left passanger kick panel by removing the panel clip. Once you’ve got the wires pushed through, open up the fuse panel by pulling down on the plastic cover then turning the 2 wing locks. I ran my wires behind and over the fuse panel making sure they wouldn’t pinch or interfere with any of the other components. I soldered the Add-a-Circuits to each of the 3 wires and dropped them into the appropriate fuse slots:

    Fuse #38 = +12V constant (RED wire)
    Fuse #44 = +12V when Ignition is ON (ORANGE wire)
    Fuse #46 = +12V when tail lights are ON (WHITE wire)

    I checked my fuse locations using a circuit tester and found these to be proper, so if you are unsure please perform this method for assurance.

    I used 1A fuses for the Defi Add-a-Circuit fuse locations. I contacted Defi and the tech confirmed that this would NOT hurt the gauge in the event of a short. Another method would have been to permanently short the Add-a-Circuit, but I didn’t feel the need to do this for my install.

    Now I ran the BLACK wire (ground) from the Defi gauge to a stock grounding point found behind the left drivers kick panel. Remove the stock ground using an 8mm socket. I stripped the end of the BLACK wire and pinched it in a ¼” ring terminal. I placed it behind the stock ground and bolted everything back up.

    Nice and neat FK!

    Now it’s time for a test before buttoning everything back up. Plug the Defi connectors into the gauge, reconnect the -12V to the battery and turn the ignition on. If everything was done correctly, the gauge should perform it’s startup sequence. Start the car and check for sensor readings. Give it a little gas and watch the needle dance – if you reached this part you are in good shape. If this didn't work out, re-check your soldering points and fuse placement.

    Reinstall reverse of removal, have a beer and enjoy your snazzy new Defi.

    If anyone has any questions, please contact me via PM. I also must give thanks to to my wonderful girlfriend for helping make this install a breeze.


    422 Posts
    nice write up. seems a little excessive removing all the trim pieces but it helps for anyone wanting to do the same. Can you take a couple pics of the gauge/mount final product since you've only got night pics posted?

    14 Posts
    Discussion Starter · #4 ·
    [quote author=Trinity link=topic=135931.msg2931761#msg2931761 date=1234455132]
    nice write up. seems a little excessive removing all the trim pieces but it helps for anyone wanting to do the same. Can you take a couple pics of the gauge/mount final product since you've only got night pics posted?


    I don't know why someone would want to work with the trim pieces still in place. Not only would you waste more time trying to manuver/work around them vs removing them, but you can't see/cleanly route all of your wires. Removing all those trim pieces takes less than 5 minutes :).

    I will snap some daytime photos on the weekend.

    144 Posts
    Fuse number 38 is labeled as Stop light in my fuse box. Good write up though. I ended up using fuse #69, but it's not a constant 12v. I'll need to switch it to something else.

    231 Posts
    Ended up going with the reverse light fuse instead of #38.

    Also for those using the vent pod. 2 steps.

    1. Gentle pull the flaps of the vent and it'll pop right out
    2. Stick you hand into the vent and try to push against the insides because you need to turn that outer cup counterclockwise to unlock it and then u can just pull it out. U can try and gently use a flathead to help pry the top a little once u line up the "lock" to the gap on the top (sorry not sure how else to describe it)...kind of like how ur vacuum brush attaches to the hose
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